I have asked the same question in different places and I'm sure that the product management has read this.
It seems to me that oracle tries to let designer silently die and propagate sql devleoper data modeling as the next hype.
Not enough - we miss Translation Hub too from developer suite too.

There is a new statement of direction available at http://www.oracle.com/technology/products/forms/pdf/10g/ToolsSOD.pdf.

In this statement of direction you can find the following:

Oracle Designer

As stated in earlier versions of this document, since Oracle Designer 10g there have been no
major new features although the product continues to be supported and development effort is
focused on stability and bug fixes. Oracle Designer is not released as a component of Oracle
Fusion Middleware 11g but will remain as a component in the Oracle Developer Suite 10g.
Future releases of Oracle Designer and support timelines will be within the Oracle Developer
Suite 10g release.

What does this mean? Do I have to install in parallel 10g Developer Suite to 1xg till 2017?
Will there be updates of 10g Developer Suite to next operating systems like windows 7 or database like 11.2?
How should reverse engineering work with new 11g Forms file format?

What does this mean? Do I have to install in parallel 10g Developer Suite to 1xg till 2017?
Will there be updates of 10g Developer Suite to next operating systems like windows 7 or database like 11.2?
How should reverse engineering work with new 11g Forms file format?

- There will be no further release after 10g Designer.
- 10g Designer is not desupported (whatever that means).
If you look at support matrix, then there will be a desupport of release 10g in near feature.
But sales states too, that a support of future databases and operating systems are planned for designer 10g.
- In related patches there will be no new feature support for database or forms generators and so on.

So you have to install 10g Designer and 11 FMW in parallel, if you want further use 10g Designer.
Generate your forms and convert it to 11 FMW afterward.
No reverse engineering is possible in this scenario.

I can remember that back in 1998, when I was at Oracle, a certain Mr Ellison stated that the then Designer/2000 was "the most important product Oracle has developed since the database." Oh how things have changed!!

I can understand Oracle's reluctance in further development of a client server tool such as Designer, however, stating that a tool like SQL Developer Data Modeler could be used to replace the functionality we have in Designer, is, to be frank, an insult to our intelligence. SQL Developer Data Modeler may be fine for small projects, but in organisations where large scale multi-user development takes place, it is next to useless.

In my opinion, Oracle has missed an opportunity by going down the SQL Developer Data Modeler and JDeveloper route, when they could have continued development of a repository based tool that would support both the traditional Designer functionality and Java/UML.

More and more organisations, I work with, are looking outside of Oracle for 'Design' tools, and I feel sure this trend will continue. Having been a user of the Oracle CASE tools since the late 80s from the old Case Dictionary/Designer through to the current version, I feel more than a touch of sadness at its' impending demise, as it surely will. At least I can look forward to retirement in the coming year!!

I also still like the Oracle Designer tool. For Oracle Designer users there is still no fitting alternative. Yes, there is SQL Developer Data Modeler and JDeveloper but this could be used when redesigning your application.

Oracle Designer is now getting to a point where we are missing functionality which is inside the newer Oracle Database versions or newer Forms versions. To bad for a tool which is still used in many organizations.

Isn't there an option for Oracle to open source Oracle designer so it can be extended with new Oracle Database/Forms functionality?

There are some ways to extend the current Designer, but no-one has done much with them. I think the same would result from making Designer an open source project - no-one would put the resources into it. I've talked to people who have seen Designer's source code. According to some it has patches upon patches - very messy. Heck, I wrote a SQL Developer extension to browse the Designer Repository, and open sourced it on http://samplecode.oracle.com/ but no-one has come forward to help work on it. It worked on SQL Developer 1.5, but doesn't on 2.1.1, so I'm working to fix it. But it is low priority, because I don't use Designer much anymore.

I think that SDDM is your best bet. There is a much better chance that if it doesn't do something you need it to do, it has developers who can fix it, change it, or add onto it.

The issue with SDDM, as I mentioned above, it's not, at present, that suitable for large multi-user development. It needs to be a repository based tool, like Designer, and offer all that Designer does and more. Hopefully it may do in the future.

To be honest, if Designer disappears, then in my opinion people would be better off looking at other tools, such as IBM Rational System Architect, which despite many failings, is better than SDDM